Abysmal Read/Write Speed

[cookie17]

System:
OS: Debian GNU/Linux 11 (bullseye) x86_64
Kernel: 5.15.79+truenas
Uptime: 10 days, 21 hours, 30 mins
CPU: Intel Pentium Silver J5040 (4) @ 3.200GHz
GPU: Intel GeminiLake [UHD Graphics 605]
Memory: 27909MiB / 31948MiB
Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller (rev 05)


Storage:

1 x MIRROR | 2 wide | 7.28 TiB.

____________________


Iperf network bandwidth test:

iperf3 -c 192.168.1.203
Connecting to host 192.168.1.203, port 5201
[ 5] local 192.168.1.136 port 33912 connected to 192.168.1.203 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 18.0 MBytes 151 Mbits/sec 0 865 KBytes
[ 5] 1.00-2.00 sec 15.0 MBytes 126 Mbits/sec 0 878 KBytes
[ 5] 2.00-3.00 sec 16.2 MBytes 136 Mbits/sec 0 878 KBytes
[ 5] 3.00-4.00 sec 16.2 MBytes 136 Mbits/sec 0 923 KBytes
[ 5] 4.00-5.00 sec 15.0 MBytes 126 Mbits/sec 0 923 KBytes
[ 5] 5.00-6.00 sec 15.0 MBytes 126 Mbits/sec 0 984 KBytes
[ 5] 6.00-7.00 sec 16.2 MBytes 136 Mbits/sec 0 984 KBytes
[ 5] 7.00-8.00 sec 15.0 MBytes 126 Mbits/sec 0 984 KBytes
[ 5] 8.00-9.00 sec 16.2 MBytes 136 Mbits/sec 0 984 KBytes
[ 5] 9.00-10.00 sec 15.0 MBytes 126 Mbits/sec 0 984 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.00 sec 158 MBytes 133 Mbits/sec 0 sender
[ 5] 0.00-10.08 sec 156 MBytes 130 Mbits/sec receiver


Ethtool:

ethtool enp1s0
Settings for enp1s0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
2500baseT/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
2500baseT/Full
Advertised pause frame use: Symmetric Receive-only
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Link partner advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Link partner advertised pause frame use: Symmetric
Link partner advertised auto-negotiation: Yes
Link partner advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Auto-negotiation: on
master-slave cfg: preferred slave
master-slave status: slave
Port: Twisted Pair
PHYAD: 0
Transceiver: external
MDI-X: Unknown
Supports Wake-on: pumbg
Wake-on: d
Link detected: yes

________________________________

Disk write speed test (dd):

dd if=/dev/zero of=test1.img bs=1G count=1 oflag=dsync
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 1.20111 s, 894 MB/s


_________________________________________


Even though everything seems fine, read/write speeds over SMB or NFS are basically capped at 10 MBytes / sec.

 

[Ericloewe]

Clearly your network is at fault, as evidenced by the iPerf results.
Knowing nothing else, I'd start by investigating the Realtek NIC.

 

[cookie17]

After a few hours of debugging, I conclude that this NIC does not like ethernet over powerline for some reason. When connected directly into the router file transfer at the maximum possible speed.

 

[ChrisRJ]

Powerline is a crappy technology and the advertised speeds are usually completely unrealistic. Actually, you can be happy if you even get a stable connection (at whatever speed).

 

[2twisty]

Powerline ethernet is fine for web browsing, but there are lots of retransmits on that tech, and you have to remember that with the 60Hz AC in those power lines, your ethernet frames have to compete. Also wires in your house are giant antennae. They can pick up spurious signals as well.

For something like NAS storage, you want a wired connection wherever possible.